Bleaching composition.



U IT D STATES PATENT OFFICE.

ARMAND STIEG-ELMANN AND ERICH DEHNEL, OF LUDWIGSHAFEN-ON-THE-RHINE,

GERMANY, .ASSIGNORS TO BADISCHE ANILIN z z SODA FABRIK, F LUDWIGSHAIFEN- ON-THE-RH INE, GERMANY, A CORPORATION OF GERMANY.

BLEACHING COMPOSITION.

No Drawing.

We have discovered a new composition of matter which consists of solid anhydrous sodium hydrosulfite and zinc dust, and which can be used as a bleaching agent. The solid anhydrous sodium hydrosulfite can be obtained, for example, according to the process claimed in Patent No. 795,755

and iii-the pure state possesses a composition corresponding to the formula Na S O Our new bleaching agent is as stable in the form of powder as the solid anhydrous sodium hydrosulfite itself and possesses advantages over this body in some of its applications. In particular, the solutions obtained by mixing the new agent withwater are more stable than are sodium hydrosulfite solutions free from zinc dust, and further they have a greater bleaching action in some cases. The new mixture is preferable to anhydrous sodium hydrosulfite itself for blea ching purposes in cases where the bleaching action I has to beprolonged, forthe greater stability of the solutions makes their use moreeco- Specificationof Letters Patent;

Application filed November 10, 1909. Serial No. 527,316.

Patented Feb. 14, 1911.

nomical than that of sodium hydrosulfite itself, the solutions of which rapidly deteriorate in activity. Thus the new agent is especially useful for bleaching leather, glue, and feathers and the cheaper varieties of straw.

As an example of the composition of the new bleaching agent We instance (without limitin ourselves thereto) a mixtureof one i hundre parts by weight of commercial SOlld anhydrous sodium hydrosulfite (containing,-say, about ninety per cent. of pure anhydrous sodium hydrosulfite Na S O and ten parts by weight of zinc dust. These are thoroughly mixed together.

Now what we claim'is 1. The new bleaching composition consisting of solid anhydrous sodium hydrosulfite and zinc dust.

-2. The new bleaching composition consisting of one hundred parts of solid anhydrous sodium hydrosulfite and ten parts of zinc dust.

In testimony whereof we have hereunto set our hands in.the presence of two sub'- I scribing witnesses.

ARMAND STIEGELMANN. ERIOH DEHNEL.

Witnesses J. ALno. LLOYD, W. W. SCHMIDT. 

